|Holland, Jim - Jim|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2004
Publication Date: 10/30/2004
Citation: Tarter, J.A., Holland, J.B. 2004. Detecting epistasis through the use of double-introgression near-isogenic lines of maize [abstracts]. Agronomy Abstracts: p.135. Poster No. 195.
Technical Abstract: Epistasis is an interaction between loci that is observed on some phenotype. Detecting epistatic interactions in typical mapping populations is confounded by segregation of the genetic background. This problem can be reduced through the use of near-isogenic lines (NILs). Objectives of this study were to test for evidence of epistatic interactions, their frequencies, and magnitudes in both inbred and hybrid combinations of maize. Using marker-assisted selection, 127 double introgression near-isogenic lines (dNILs) were developing using B73 as the recurrent parent and two introgressions from the donor parent Tx303. Epistasis was detected by comparing dNILs to their specific parental single-introgression NILs. After the first year of testing, 54 dNIL inbred lines (43%) exhibited epistasis for all six agronomic traits measured. Epistasis for only one trait was detected in 32 lines (25%), and epistasis for two traits simultaneously was detected in 17 lines (14%). In the hybrid trials, 37 dNILs (29%) exhibited epistasis for eight of the ten agronomic traits measured. Twenty-five lines (20%) exhibited epistasis for one trait while 10 lines (8%) exhibited epistasis for two traits simultaneously. Only 5 epistatic genetic combinations were in common between the inbred and hybrid lines.